The only thing I can think of is that the included version of astyle doesn't work on your system.
I can't really help you any more than suggesting you try to build astyle (from http://astyle.sourceforge.net or something).
It DID what?
(What output if any?)
By the way, you might be right with the 32-bit/64-bit thing, since I only got a "Permission denied" error.
I am, however, certain that astyle for some reason can't be executed and that is what is generating the error.
I was getting the same errors and I checked out runtime/bin/astyle-osx. When I tried to run it from the Terminal I got a "Permission denied" error, so I checked the permissions and saw that those matched.
The problem was that when the file was downloaded, it got put in the special quarantine (the one that asks you if you're sure you want to open the downloaded file), so I opened it from Finder and chose yes.
This fixed the problem for me.